Occurrence Cause Tsunami

Origin of Tsunami - The word tsunami comes from the Japanese. Tsu which means harbor and nami means wave.Tsunamis often happen in Japan.History of Japan recorded at least 197 tsunamis have occurred in Japan. On several occasions, equated with the tsunami tidal waves. In recent years, this perception has been declared no longer appropriate, particularly within the research community, because the tides have nothing to do with the tsunami. This perception is popular because the first appearance of the tsunami that resembles a high tide.Tsunamis and tidal waves are both produced a wave of water that moves onto land, but in the tsunami, the wave motion is much larger and longer, so memberika impression as a very high tide. Although the notion that equates with "the tides" includes "resemblance" or "similar character" to surge, this understanding is no longer appropriate. The tsunami not only limited to the harbor. Because of the geological and oceanographically highly not recommend to use the term.There are only a few local language which has the same meaning with these destructive waves. Aazhi Peralai in Tamil language, ie beuna or Alon buluëk (according to dialect) in the language of Aceh is an example. For the record, in Tagalog version of Austronesian, the main language in the Philippines, Alon means "wave." On Simeulue Island, west coast of Sumatra, Indonesia, in Bahasa Defayan, smong mean a tsunami.While in Bahasa Sigulai, Emong mean a tsunami.

Causes of Occurrence of Tsunamis

Tsunamis can occur if an interruption occurs that causes the movement of large amounts of water, such as volcanic eruptions, earthquakes, landslides or meteorite that fell to earth. However, 90% of the tsunami is an earthquake under the sea. In recording the history of some of the tsunami caused by the volcano eruption, for example when the eruption of Mount Krakatoa. Vertical movement on the Earth's crust, can lead to the ocean floor rise or fall abruptly, resulting in disruption of water balance that is above them. This resulted in the energy flow of sea water, which when it reached the coast into a large wave that caused the tsunami.The speed of tsunami waves depends on the depth of the sea where the waves occurs, where the speed can reach hundreds of kilometers per hour. When the tsunami reaches the shore, its speed will be around 50 km / h and its energy is very damaging coastal areas in its path. In the midst of the tsunami wave height sea only a few centimeters to several meters, but when it reaches shore wave height can reach tens of meters due to a buildup of the water. When the tsunami reaches the coast of the mainland will crawl away from the coastline with a range of several hundred meters can even be a few kilometers.This vertical motion can occur on the earth fault or the fault. The earthquake also occurred in the subduction area, where the oceanic plate menelusup down the continental shelf.The landslide that occurred on the seabed and volcanic debris can also lead to disruption of sea water which can generate a tsunami. The earthquake caused perpendicular movement of the earth layer. As a result, the sea rose and fell abruptly so that the balance of sea water which is above them disturbed. Similarly, cosmic objects or meteor that fell from above. If the size of a meteor or landslide is big enough, can occur megatsunami reach hundreds of meters high.